1. Field of the Invention
The present invention relates to a camera system and an image processing method suitably applied to a case of efficiently compression-coding RAW data obtained from image pickup elements of various kinds of arrangement systems and decompressing the compression-coded RAW data, for example.
2. Description of the Related Art
An image pickup device using an image pickup element of a Bayer arrangement is generally known in the past. Such an image pickup element captures image light of a subject via a color filter, and outputs an image signal according to the intensity of the image light. Then, a subsequent processing section subjects the image signal to predetermined processing, whereby the image pickup device can display an image on a viewfinder or an external display device.
In general, a camera system used for live broadcasts and the like includes a camera section used as an image pickup device and having an image pickup element and a CCU (Camera Control Unit) section installed at a place distant from the camera section. A connection between the camera section and the CCU section is established by using a transmitting composite camera cable or the like, and the CCU section makes settings in the camera section. At this time, the CCU section performs signal processing on an image transmitted from the camera section with high accuracy and in real time. In addition, the existing camera system handles images of high resolution such as 4K images and 8K images or images of high frame rates such as 60 P/240 P, and thus handles an enormous amount of data. Thus, the camera section transmits RAW image data to the CCU section as it is, and the CCU section performs camera signal processing.
Incidentally, 8K denotes an example of specifications for high resolution such as 8192 samples×4320 lines. 4K denotes an example of specifications for lower resolution than 8K such as 4096 samples×2160 lines. 2K denotes an example of specifications for lower resolution than 4K such as 2048 samples×1080 lines.
Japanese Patent Laid-Open No. 2002-247376 (hereinafter referred to as Patent Document 1) describes compression of RAW data (image data before color interpolation) obtained from an image pickup element of the Bayer arrangement as it is by JPEG (joint photographic experts group) or the like.
Japanese Patent Laid-Open No. 2003-125209 (hereinafter referred to as Patent Document 2) describes techniques for separately performing image compression of each of components of G1, G2, R, and B and a concrete example using wavelet compression as methods for compressing RAW data obtained from an image pickup element of the Bayer arrangement.